#define _CRT_SECURE_NO_WARNINGS 1

#include<stdio.h>
int F(int x,int y)
{
	int z = (x + y) / 2;
	return z;

}

int main()
{
	int num1 = 0;
	int num2 = 0;
	scanf("%d%d", &num1, &num2);
	int avg=F(num1, num2);
	printf("%d", avg);
	return 0;
}